Authorities in Japan downgraded a tsunami warning to an advisory after a powerful struck off its northeastern coast on Monday (April 20).
The quake, which hit at 4:53 p.m. local time, initially . However, waves of up to 80 cm were recorded about two hours later, prompting officials to ease the warning level.
No casualties reported so far
Japan’s top government spokesperson Minoru Kihara said there were no immediate reports of casualties or major damage as of Monday evening in Tokyo.
Precautionary evacuation orders were issued in several coastal towns, including Otsuchi and Kamaishi, both of which were severely affected during the 2011 Japan earthquake and tsunami.
Public broadcaster NHK reported that bullet train services were temporarily halted and some motorways were closed following the tremor.
Government warns of elevated megaquake risk
Officials cautioned that the likelihood of a larger has increased in the near term.
The probability of a magnitude 8 or stronger quake along the Japan Trench and Kuril Trench typically stands at around 0.1% over a week but has risen to about 1% in the week following Monday’s quake.
“Please take anti-disaster steps, while embracing the idea that one must protect one’s own life,” a government official said.
Seismic details and potential impact
The earthquake measured an “upper 5” on Japan’s seismic intensity scale, strong enough to make movement difficult and potentially cause damage to weaker structures.
According to the Japan Meteorological Agency, the quake struck at a depth of 20 km beneath the Pacific Ocean.
Officials warned that a 3-metre tsunami could inundate low-lying areas, flooding buildings and posing serious risks to anyone caught in the currents.
No issues at nuclear facilities
Utility operators Hokkaido Electric Power Company and Tohoku Electric Power Company said there were no abnormalities at their idled nuclear plants in the affected region.
Japan’s high seismic risk
Situated along the Ring of Fire, Japan is among the most earthquake-prone countries in the world, accounting for roughly 20% of global earthquakes of magnitude 6.0 or higher.
The country continues to remain on alert as authorities monitor aftershocks and potential tsunami activity following the latest tremor.
(With Reuters inputs)
